void VG_(gdbserver_exit) (ThreadId tid, VgSchedReturnCode tids_schedretcode)
{
dlog(1, "VG core calling VG_(gdbserver_exit) tid %d will exit\n", tid);
if (remote_connected()) {
/* Make sure vgdb knows we are about to die and why. */
switch(tids_schedretcode) {
case VgSrc_None:
vg_assert (0);
case VgSrc_ExitThread:
case VgSrc_ExitProcess:
gdbserver_process_exit_encountered ('W', VG_(threads)[tid].os_state.exitcode);
call_gdbserver (tid, exit_reason);
break;
case VgSrc_FatalSig:
gdbserver_process_exit_encountered ('X', VG_(threads)[tid].os_state.fatalsig);
call_gdbserver (tid, exit_reason);
break;
default:
vg_assert(0);
}
} else {
dlog(1, "not connected\n");
}
/* Tear down the connection if it still exists. */
VG_(gdbserver) (0);
}
Bool VG_(gdbserver_activity) (ThreadId tid)
{
Bool ret;
busy++;
if (!gdbserver_called)
call_gdbserver (tid, init_reason);
switch (remote_desc_activity("VG_(gdbserver_activity)")) {
case 0: ret = False; break;
case 1: ret = True; break;
case 2: call_gdbserver (tid, init_reason); ret = False; break;
default: vg_assert (0);
}
busy--;
return ret;
}
Bool VG_(gdbserver_report_signal) (Int sigNo, ThreadId tid)
{
dlog(1, "signal %d tid %d\n", sigNo, tid);
/* if gdbserver is currently not connected, then signal
is to be given to the process */
if (!remote_connected()) {
dlog(1, "not connected => pass\n");
return True;
}
/* if gdb has informed gdbserver that this signal can be
passed directly without informing gdb, then signal is
to be given to the process. */
if (pass_signals[sigNo]) {
dlog(1, "pass_signals => pass\n");
return True;
}
/* indicate to gdbserver that there is a signal */
gdbserver_signal_encountered (sigNo);
/* let gdbserver do some work, e.g. show the signal to the user */
call_gdbserver (tid, signal_reason);
/* ask gdbserver what is the final decision */
if (gdbserver_deliver_signal (sigNo)) {
dlog(1, "gdbserver deliver signal\n");
return True;
} else {
dlog(1, "gdbserver ignore signal\n");
return False;
}
}
Bool VG_(gdbserver_report_signal) (vki_siginfo_t *info, ThreadId tid)
{
dlog_signal("VG_(gdbserver_report_signal)", info, tid);
/* if gdbserver is currently not connected, then signal
is to be given to the process */
if (!remote_connected()) {
dlog(1, "not connected => pass\n");
return True;
}
/* if gdb has informed gdbserver that this signal can be
passed directly without informing gdb, then signal is
to be given to the process. */
if (pass_signals[target_signal_from_host(info->si_signo)]) {
dlog(1, "pass_signals => pass\n");
return True;
}
/* indicate to gdbserver that there is a signal */
gdbserver_signal_encountered (info);
/* let gdbserver do some work, e.g. show the signal to the user.
User can also decide to ignore the signal or change the signal. */
call_gdbserver (tid, signal_reason);
/* ask gdbserver what is the final decision */
if (gdbserver_deliver_signal (info)) {
dlog(1, "gdbserver deliver signal\n");
return True;
} else {
dlog(1, "gdbserver ignore signal\n");
return False;
}
}
void VG_(gdbserver_report_fatal_signal) (const vki_siginfo_t *info,
ThreadId tid)
{
dlog_signal("VG_(gdbserver_report_fatal_signal)", info, tid);
if (remote_connected()) {
dlog(1, "already connected, assuming already reported\n");
return;
}
VG_(umsg)("(action on fatal signal) vgdb me ... \n");
/* indicate to gdbserver that there is a signal */
gdbserver_signal_encountered (info);
/* let gdbserver do some work, e.g. show the signal to the user */
call_gdbserver (tid, signal_reason);
}
void VG_(helperc_CallDebugger) ( HWord iaddr )
{
GS_Address* g;
// For Vg_VgdbFull, after a fork, we might have calls to this helper
// while gdbserver is not yet initialized.
if (!gdbserver_called)
return;
if (valgrind_single_stepping() ||
((g = VG_(HT_lookup) (gs_addresses, (UWord)HT_addr(iaddr))) &&
(g->kind == GS_break))) {
if (iaddr == HT_addr(ignore_this_break_once)) {
dlog(1, "ignoring ignore_this_break_once %s\n",
sym(ignore_this_break_once, /* is_code */ True));
ignore_this_break_once = 0;
} else {
call_gdbserver (VG_(get_running_tid)(), break_reason);
}
}
}
void VG_(gdbserver) ( ThreadId tid )
{
busy++;
/* called by the rest of valgrind for
--vgdb-error=0 reason
or by scheduler "poll/debug/interrupt" reason
or to terminate. */
if (tid != 0) {
call_gdbserver (tid, core_reason);
} else {
if (gdbserver_called == 0) {
dlog(1, "VG_(gdbserver) called to terminate, nothing to terminate\n");
} else if (gdbserver_exited) {
dlog(0, "VG_(gdbserver) called to terminate again %d\n",
gdbserver_exited);
} else {
gdbserver_terminate();
gdbserver_exited++;
}
}
busy--;
}
void VG_(gdbserver_report_fatal_signal) (Int vki_sigNo, ThreadId tid)
{
dlog(1, "VG core calling VG_(gdbserver_report_fatal_signal) "
"vki_nr %d %s gdb_nr %d %s tid %d\n",
vki_sigNo, VG_(signame)(vki_sigNo),
target_signal_from_host (vki_sigNo),
target_signal_to_name(target_signal_from_host (vki_sigNo)),
tid);
if (remote_connected()) {
dlog(1, "already connected, assuming already reported\n");
return;
}
VG_(umsg)("(action on fatal signal) vgdb me ... \n");
/* indicate to gdbserver that there is a signal */
gdbserver_signal_encountered (vki_sigNo);
/* let gdbserver do some work, e.g. show the signal to the user */
call_gdbserver (tid, signal_reason);
}
/* Using ptrace calls, vgdb will force an invocation of gdbserver.
VG_(invoke_gdbserver) is the entry point called through the
vgdb ptrace technique. */
void VG_(invoke_gdbserver) ( int check )
{
/* ******* Avoid non-reentrant function call from here .....
till the ".... till here" below. */
/* We need to determine the state of the various threads to decide
if we directly invoke gdbserver or if we rather indicate to the
scheduler to invoke the gdbserver. To decide that, it is
critical to avoid any "coregrind" function call as the ptrace
might have stopped the process in the middle of this (possibly)
non-rentrant function. So, it is only when all threads are in
an "interruptible" state that we can safely invoke
gdbserver. Otherwise, we let the valgrind scheduler invoke
gdbserver at the next poll. This poll will be made very soon
thanks to a call to VG_(force_vgdb_poll). */
int n_tid;
vg_assert (check == 0x8BADF00D);
if (busy) {
interrupts_while_busy++;
give_control_back_to_vgdb();
}
interrupts_non_busy++;
/* check if all threads are in an "interruptible" state. If yes,
we invoke gdbserver. Otherwise, we tell the scheduler to wake up
asap. */
for (n_tid = 1; n_tid < VG_N_THREADS; n_tid++) {
switch (VG_(threads)[n_tid].status) {
/* interruptible states. */
case VgTs_WaitSys:
case VgTs_Yielding:
if (vgdb_interrupted_tid == 0) vgdb_interrupted_tid = n_tid;
break;
case VgTs_Empty:
case VgTs_Zombie:
break;
/* non interruptible states. */
case VgTs_Init:
case VgTs_Runnable:
interrupts_non_interruptible++;
VG_(force_vgdb_poll) ();
give_control_back_to_vgdb();
default: vg_assert(0);
}
}
/* .... till here.
From here onwards, function calls are ok: it is
safe to call valgrind core functions: all threads are blocked in
a system call or are yielding or ... */
dlog(1, "invoke_gdbserver running_tid %d vgdb_interrupted_tid %d\n",
VG_(running_tid), vgdb_interrupted_tid);
call_gdbserver (vgdb_interrupted_tid, vgdb_reason);
vgdb_interrupted_tid = 0;
dlog(1,
"exit invoke_gdbserver running_tid %d\n", VG_(running_tid));
give_control_back_to_vgdb();
vg_assert2(0, "end of invoke_gdbserver reached");
}
Bool VG_(is_watched)(PointKind kind, Addr addr, Int szB)
{
Word n_elems;
GS_Watch* g;
Word i;
Bool watched = False;
const ThreadId tid = VG_(running_tid);
if (!gdbserver_called)
return False;
n_elems = VG_(sizeXA) (gs_watches);
Addr to = addr + szB; // semi-open interval [addr, to[
vg_assert (kind == access_watchpoint
|| kind == read_watchpoint
|| kind == write_watchpoint);
dlog(1, "tid %d VG_(is_watched) %s addr %p szB %d\n",
tid, VG_(ppPointKind) (kind), C2v(addr), szB);
for (i = 0; i < n_elems; i++) {
g = index_gs_watches(i);
switch (g->kind) {
case software_breakpoint:
case hardware_breakpoint:
break;
case access_watchpoint:
case read_watchpoint:
case write_watchpoint:
if (to <= g->addr || addr >= (g->addr + g->len))
/* If no overlap, examine next watchpoint: */
continue;
watched = True; /* We have an overlap */
/* call gdbserver if access kind reported by the tool
matches the watchpoint kind. */
if (kind == access_watchpoint
|| g->kind == access_watchpoint
|| g->kind == kind) {
/* Watchpoint encountered.
If this is a read watchpoint, we directly call gdbserver
to report it to gdb.
Otherwise, for a write watchpoint, we have to finish
the instruction so as to modify the value.
If we do not finish the instruction, then gdb sees no
value change and continues.
For a read watchpoint, we better call gdbserver directly:
in case the current block is not gdbserved, Valgrind
will execute instructions till the next block. */
/* set the watchpoint stop address to the first read or written. */
if (g->addr <= addr) {
VG_(set_watchpoint_stop_address) (addr);
} else {
VG_(set_watchpoint_stop_address) (g->addr);
}
if (kind == write_watchpoint) {
/* Let Valgrind stop as early as possible after this instruction
by switching to Single Stepping mode. */
valgrind_set_single_stepping (True);
invalidate_current_ip (tid, "m_gdbserver write watchpoint");
} else {
call_gdbserver (tid, watch_reason);
VG_(set_watchpoint_stop_address) ((Addr) 0);
}
return True; // we are watched here.
}
break;
default:
vg_assert (0);
}
}
return watched;
}
